JP3274577B2 - Turbid water treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbid water treatment apparatus for removing suspended substances in turbid water generated during foundation work such as construction work and draining the water.

[0002]

2. Description of the Related Art Turbid water generated during foundation work such as construction work is different from factory drainage and is usually discharged for a short period of time and contains no harmful metals. Drainage into gutters and rivers, and installation of a simple sedimentation tank to drain supernatant water. If the turbid water is drained without being treated, sludge accumulates in the sewer pipes and the rivers are polluted and greatly affected the natural environment. It has been required by prefectural pollution prevention regulations. As a purification treatment of the turbid water, a coagulation sedimentation treatment with a chemical is often employed.

Generally, suspended particles suspended in water are negatively charged and repel each other, so that they are stable in a dispersed state. Therefore, coagulation sedimentation treatment with chemicals adds a coagulant with a positive charge to turbid water to electrically neutralize the suspended particles that are dispersed and agglomerates the particles. It is a method of increasing. Aluminum sulfate, basic aluminum chloride, ferric chloride and the like are used as a flocculant used for the flocculation and precipitation treatment. In addition, a polymer flocculant such as sodium alginate and polyacrylamide is also used, and the floating particles are flocculated by utilizing the adsorptive crosslinking action between the particles.

As the coagulation / sedimentation treatment apparatus, there is provided a horizontal treatment apparatus having a mixing tank for mixing wastewater and a coagulant, a floc formation tank for growing flocs, and a sedimentation tank for retaining and sedimenting the grown flocs. In addition, a vertical treatment apparatus for recirculating floc generated by mixing wastewater and a flocculant is used.

[0005]

When turbid water is purified by coagulation and sedimentation with a chemical as described above, the hydroxide of the chemical used as the coagulant and the chemical itself are discharged into a river or the like. There is a danger that environmental pollution may occur due to the used chemicals and the equipment becomes large.

A turbid water purifying apparatus for coagulating suspended particles in turbid water without using a coagulant in order to prevent environmental pollution caused by such chemicals is disclosed in, for example, JP-A-4-2982.
No. 84 discloses this. In this turbid water purification device, aluminum anode electrodes and stainless steel cathode electrodes are alternately arranged along the turbid water flow path, and the suspended particles in the turbid water are neutralized by cations generated from the anode electrode. When this turbid water purification device is used, it is not necessary to add or purify a flocculant, but if it is used for a long time, the aluminum anode electrode is consumed and it is not easy to replace it.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such disadvantages, and has as its object to provide a turbid water treatment apparatus which can be easily transported to a construction site or the like and can be used stably for a long time. .

[0008]

A turbid water treatment apparatus according to the present invention has an electrode tank, an electrode switching means, a separation tank and a floc discharge control means provided at a stage subsequent to the electrode tank, and comprises an electrode tank.
Consists of an aluminum alloy plate connected to the anode of a DC power supply
Made of aluminum alloy connected to electrodes and cathode of DC power supply
A plurality of electrodes are alternately arranged along the flow direction of the muddy water, and the electrode switching means switches the connection between the DC power supply and each electrode at predetermined time intervals to switch the polarity of each electrode. It has a cylinder and an outer cylinder, the inner cylinder is provided vertically in the outer cylinder, has a turbid water inlet at the upper end, and a plurality of turbid water outlets is provided on the lower side wall in a plurality of stages in the vertical direction. A plurality of partition plates are horizontally mounted, each partition plate has a turbid water passage at a different position for each adjacent partition plate, the outer cylinder has a conical shape tapered at the bottom, and has a sludge discharge port at the lower end. The upper end has a flood discharge port, a stirring blade is provided in the lower conical section, and the upper limit of floc detection that determines the upper limit of floc accumulation in the middle part between the upper overflow discharge port and the turbid water outlet of the inner cylinder. Means, and the flock discharge control means includes a
The lock is the turbid water outlet of the inner cylinder due to the height of the flock.
Detecting the time to decrease to the top position in advance
A set discharge timer, wherein the flock upper limit detecting means is provided.
The stirring blades when detecting the limit height of flock
While rotating, the floe accumulated from the sludge discharge port at the bottom of the outer cylinder
Discharge of sludge including wastewater started and the discharge timer is set
The discharge of sludge is stopped when the time is reached .

[0009] Another turbid water treatment apparatus according to the present invention comprises an electrode
A tank, an electrode switching means, and a separation tank disposed after the electrode tank;
And a floc discharge control means.
Electrode made of aluminum alloy plate connected to the anode of
The electrode made of aluminum alloy connected to the cathode of the source
A plurality of sheets are alternately arranged along the flow direction, and the electrode switching means is
DC power supply and each electrode at predetermined time intervals
The connection is switched to switch the polarity of each electrode, and the separation tank is
It has a cylinder, the inner cylinder is provided vertically in the outer cylinder, and the upper end is turbid.
Water inlet, multiple turbid water outlets on lower side wall
Are provided in a plurality of stages, and a plurality of
Each partition plate is located at a different position for each adjacent partition plate.
It has a turbid water passage, and the outer cylinder has a conical shape with a tapered lower part.
It has a sludge outlet at the end and a flood outlet at the upper end,
A stirring blade is installed in the lower conical part, and the upper part overflows.
Flock accumulates between the outlet and the turbid water outlet of the inner cylinder
It has a flock upper limit detecting means for determining the upper limit position,
Set the lower limit of floc deposition at the upper end of the turbid water outlet
And a flock discharge control means.
The stage is the flock upper limit detecting means and the flock accumulation limit height
When the stirring blade is detected, the stirring blade
Open discharge of sludge including accumulated floc from sludge discharge port
First, the floc lower limit detection means
Stop discharge of sludge when it decreases to the upper end position of the exit
It is characterized by that.

[0010]

In the present invention, suspended particles contained in turbid water are neutralized and aggregated by cations generated from the anode electrode of the electrode tank, and water containing aggregated flocs is sent to the separation tank.
The floc is allowed to settle and separate from the water. The anode and cathode electrodes of the electrode tank for aggregating suspended particles contained in the muddy water are formed of an aluminum alloy plate, and an insulating film, A, is formed on the electrode surface.
prevent l ₂ 0 ₃ film is formed. The corrosion resistance of aluminum is greatly affected by its purity, and generally, the higher the purity, the better the corrosion resistance. Corrosion resistance of the aluminum by the protective action of Al ₂ 0 ₃ film generated on the surface. Thus purity is higher Al ₂ 0 ₃ film is formed easily, by an insulating film produced on the surface by using the pure aluminum electrode electrolytic efficiency is reduced. To prevent this reduction in electrolysis efficiency, Al
Constituting the anode electrode and the cathode electrode ₂ 0 ₃ film is formed hardly aluminum alloy plate.

As described above, when the aluminum alloy plate is used as an electrode for a long time, the anode electrode generating cations is consumed. Therefore, the anode electrode is switched to the cathode electrode at regular intervals, and the cathode electrode is switched to the anode electrode, thereby suppressing the consumption of the anode electrode.

Further, the separation tank is composed of an outer cylinder and an inner cylinder vertically provided in the outer cylinder, and a plurality of turbid water supplied from a turbid water inlet provided at an upper end portion of the inner cylinder is provided on a lower side wall. Force it to flow out from the outlet to the lower part of the outer cylinder. When the turbid water flows down in the inner cylinder, a plurality of partition plates prevent the floc contained in the turbid water from being broken by a sudden fall.

The floc in the muddy water that has flowed to the lower part of the outer cylinder sediments and accumulates sequentially, and accumulates above the position of the turbid water outlet of the inner cylinder. By discharging the turbid water from the turbid water outlet of the inner cylinder into the accumulated flocs, the flocs that have accumulated fine particles that are not agglomerated to an appropriate size contained in the turbid water serve as a filter to be captured and accumulated. The number of microparticles floating in the supernatant water on the flock. For this reason, the amount of sludge discharged from the lower part of the outer cylinder is controlled so that the flocks are always accumulated to the upper part of the turbid water outlet of the inner cylinder.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention. As shown in the figure, the turbid water treatment apparatus 1 includes an electrode tank 2, a separation tank 3, a power supply device 4, and a control unit 5. The electrode tank 2 aggregates suspended particles of suspended matter in the turbid water sent directly from the turbid water generation source 6 such as an excavation part of a foundation work for building work or through the sedimentation tank 7 to enlarge the particles. Yes, Figure 2
As shown in the perspective view, a plurality of sheets are alternately arranged along the flow direction A of the turbid water, and an anode electrode 21 connected to the anode of the power supply 4 and a cathode electrode 22 connected to the cathode of the power supply 4 And the turbid water passes between the anode electrode 21 and the cathode electrode 22. Anode electrode 21 and cathode electrode 2
Numeral 2 is formed of an aluminum alloy plate, and neutralizes and aggregates the negatively charged earth particles floating in the muddy water by aluminum ions which are cations generated from the anode electrode 21.

The reason why the anode electrode 21 and the cathode electrode 22 are formed of an aluminum alloy plate is to prevent the formation of an Al ₂ O ₃ film which is an insulating film on the surfaces of the anode electrode 21 and the cathode electrode 22. is there. That is, the corrosion resistance of aluminum is greatly affected by the purity, and generally, the higher the purity, the higher the corrosion resistance. The corrosion resistance of this aluminum
By the protective effect of ₂ 0 ₃ film. Thus purity is higher Al ₂ 0 ₃ film is formed easily, resulting in electrolysis efficiency is lowered by an insulating film produced pure aluminum on the surface when used in the anode electrode 21 and cathode electrode 22. This lowering of electrolysis efficiency in Al ₂ 0 ₃ film is formed hardly aluminum alloy plate to prevent form an anode electrode 21 and cathode electrode 22, since the aggregation of suspended particles in turbid water to perform stably for a long time in is there.

Also, a shower water is connected to the treated water outlet of the separation tank 3 on the inflow side of the turbid water of the anode electrode 21 and the cathode electrode 22, and sprays water on the surface of the turbid water flowing between the anode electrode 21 and the cathode electrode 22. A jetting means 23 is provided.

The turbid water outlet 24 of the electrode tank 2 is connected to the separation tank 3. The separation tank 3 has a vertical inner cylinder 31 and an outer cylinder 32. The inner cylinder 31 is provided vertically in the outer cylinder 32, and has a turbid water inlet 33 connected to the turbid water outlet 24 of the electrode tank 2 at the upper end as shown in the cross-sectional view of FIG. A plurality of turbid water outlets 34 are provided on the lower side wall in a staggered manner in a plurality of stages in the vertical direction. A plurality of partition plates 35 are horizontally mounted inside the inner cylinder 31, and each partition plate 35
Has a muddy water passage 36 at a different position for each adjacent partition plate 35. The outer cylinder 32 has a conical shape with a tapered lower portion, a sludge outlet 38 to which a motor-operated valve 37 is connected at a lower end, and a flood outlet 39 at an upper end. A stirring blade 40 is provided in the lower conical portion. The stirring blade 40 is connected to a stirring motor 41 provided at the upper end of the separation tank 3 via a gear mechanism 42 and a drive shaft 43 penetrating through the inner cylinder 31. An intermediate portion between the upper overflow outlet 39 and the turbid water outlet 34 of the inner cylinder 31 is provided with a floc upper limit detecting means 44 for determining the upper limit position of floc accumulation. The floc upper limit detecting means 44 is composed of, for example, a light transmission type sensor in which a light projector 44a and a light receiver 44b are housed in a protective tube 44c, respectively, and detects an upper limit level of flocs accumulated in the outer cylinder 32.

The power supply 4 has a portable generator and a rectifier, and supplies electric power to the electrode tank 2 and the separation tank 3 via the control unit 5. As shown in the block diagram of FIG. 4, the control unit 5 includes an electrode switching unit 51, a flock discharge control unit 52, and a discharge timer 53. The floc discharge control unit 52 drives the stirring motor 41 and the electric valve 37 when the floc upper limit detecting unit 44 detects the flocking limit height, and rotates the stirring blade 40 to discharge the sludge of the outer cylinder 32. From 38, the discharge of the sludge containing the deposited floc is started. After that, the floc discharge control unit 52 detects the time required for the accumulated flocs, which have been detected and set in the discharge timer 53, to decrease from the flocking limit height to the upper end position of the muddy water outlet 34 of the inner cylinder 31. When it reaches the stirring mode
The operation of the motor 41 and the electric valve 37 is stopped to stop the discharge of sludge.

Next, the operation of the turbid water treatment device 1 configured as described above will be described. A suction pump 8 is installed at a turbid water generation source 6 such as an excavation part of a foundation work for building work, and turbid water generated by the turbid water generation source 6 is sent to the electrode tank 2. If the turbid water sent to the electrode tank 2 contains a large amount of sand, the sand contained in the turbid water is settled in the sedimentation tank 7 and the turbid water containing no sand is removed from the electrode tank 2.
Send to The anode electrode 2 of the electrode tank 2 to which the turbid water is sent
1 and the cathode electrode 22 from the power supply 4 to the electrode switching means 51.
Is applied through the anode electrode 21 and the cathode electrode 22.
Aluminum cations are generated from the anode electrode 21 in the muddy water flowing between them. The generated aluminum cations neutralize and agglomerate the negatively charged soil particles floating in the muddy water to increase the particle size to form flocs.
When a floc is formed in this manner, the power supply device 4 starts with 1.
By supplying power with a current density of ² mA / cm ^{2 to} 1.6 mA / cm ^{2, the} aggregation effect could be exhibited.

The turbid water obtained by flocculating the suspended particles is sent to the separation tank 3. On the other hand, bubbles are generated during the electrolytic action in the electrode tank 2, and the generated bubbles are combined with some of the fine particles contained in the muddy water to form a scum on the surface of the electrode tank 2 to float and stagnate. When this scum is formed, it immediately becomes thick and hard, and the electrolytic action stops. Then, water is sprayed from the shower jetting means 23 to the scum surface to disintegrate the scum finely and put it into the muddy water, and send it to the separation tank 3 together with the flocculated suspended particles.

The turbid water flowing into the turbid water inlet 33 of the inner cylinder 31 of the separation tank 3 passes through the inner cylinder 31 and flows out of the plurality of turbid water outlets 34 on the lower side wall to the lower part of the outer cylinder 32. When the turbid water flows down in the inner cylinder 31, the turbid water passages 36 are located at different positions.
The turbid water is prevented from dropping abruptly by the plurality of partition plates 35 having, and the floc contained in the turbid water is prevented from being broken.

The floc in the muddy water sent into the outer cylinder 32 sinks in the muddy water, deposits at the lower part of the outer cylinder 32, and is separated from the supernatant water. Settling velocity V when this floc settles in water
Is generally expressed by the equation of Stocks V = g (ρs−ρ) d ² / 18μ
Can be represented by Here, g is the acceleration of gravity, ρs is the density of flocs, ρ is the density of water, d is the diameter of flocs, and μ is the viscosity coefficient of water. Therefore, the sedimentation velocity V increases as the diameter d of the floc particles increases, and sedimentation can be performed in a short time.

When the turbid water is continuously fed into the outer cylinder 32, the supernatant water separated from the flocs flows out of the overflow outlet 39 provided at the upper end of the outer cylinder 32, and is discharged to the sewage gutter or the drainage channel 10 of the river. You. When the turbid water is continuously fed into the outer cylinder 32 in this manner, the accumulation thickness of the flocs gradually increases and accumulates to a position above the position of the turbid water outlet 34 of the inner cylinder 31. In this way, if the flocs accumulate to a position above the position of the turbid water outlet 34 of the inner cylinder 31, the processing effect can be further enhanced. In other words, the turbid water is caused to flow out into the accumulated flocs, so that the flocs on which fine particles not appropriately aggregated contained in the turbid water are accumulated as a filter are captured and deposited. Therefore, the number of fine particles floating in the supernatant water flowing out from the overflow outlet 39 can be reduced.

When the processing of the muddy water is continuously performed and the accumulation thickness of the flocs in the outer cylinder 32 increases, and the upper end of the accumulated flocs is detected by the floc upper limit detecting means 44, the floc discharge control section 52 sets the stirring mode. The discharge of sludge including the accumulated floc from the sludge discharge port 38 of the outer cylinder 32 is started while rotating the stirring blade 40 by driving the motor 41 and the electric valve 37. Since the lower part of the outer cylinder 32 has a tapered conical shape when discharging the sludge, the sludge can be discharged easily. In addition, by rotating the stirring blade 40 to give the sludge to be discharged, the sludge adhering to the lower wall surface of the outer cylinder 32 can be separated and collected.

The floc discharge control unit 52 reduces the accumulated flocs set in the discharge timer 53 from the start of the sludge collection to the upper end position of the muddy water outlet 34 of the inner cylinder 31 from the limit height of the flocs. When the time until the operation is reached, the driving of the stirring motor 41 and the electric valve 37 is stopped to stop the discharge of sludge. By controlling the thickness of the flocs deposited such that the upper end of the flocs thus deposited is always located above the muddy water outlet 34 of the inner cylinder 31,
The amount of soil particles in the treated water discharged from the outer cylinder 32 can be reduced. As a result of measuring the amount of suspended solids (SS) in treated water when treating turbid water generated at building construction sites in this way, the amount of suspended solids (SS) can be reduced to about 10 ppm. The amount of suspended solids (S) specified in various standards, such as environmental standards and wastewater standards of the Water Pollution Control Law
Processing could be performed below the reference value of S).

[0026] The recovered sludge is used in a normal filter.
Dewater to a water content of about 80% using a press or centrifuge.

The above processing is continuously performed, and when a predetermined time has elapsed, the operator operates the electrode switching means 51 to switch the polarity of the anode electrode 21 and the cathode electrode 22 of the electrode tank 2. That is, if an aluminum alloy plate is used as an electrode for a long time, the electrode generating cations will be consumed. Therefore, by switching the polarity of the anode electrode 21 and the polarity of the cathode electrode 22 at regular time intervals, it is possible to prevent the electrodes from being consumed, and to stably perform the treatment for a long time.

In the above embodiment, when collecting sludge from the outer cylinder 32, the sludge discharge control is performed according to the time set in the discharge timer 53, and the upper end of the deposited floc is always in the turbid water outlet of the inner cylinder 31. 34, the turbid water outlet 3 of the inner cylinder 31 has been described.
A floc lower limit detecting means similar to the floc upper limit detecting means 44 may be provided at the upper end position of the block 4, and the discharge of the sludge may be stopped when the upper surface of the accumulated floc is below the installation position of the floc lower limit detecting means. .

[0029]

As described above, the present invention prevents the formation of an insulating film on the surface by forming an electrode of an electrode tank for aggregating suspended particles contained in turbid water from an aluminum alloy plate. Of the anode electrode is switched at regular intervals to prevent the anode electrode from being consumed, so that the suspended particles contained in the muddy water can be aggregated stably for a long period of time.

Further, the separation tank is constituted by an outer cylinder and an inner cylinder provided vertically in the outer cylinder, and a plurality of turbid water supplied from a turbid water inlet provided at an upper end of the inner cylinder is provided on a lower side wall. When forcibly flowing out from the outlet to the lower part of the outer cylinder, a plurality of partition plates having turbid water passages at different positions prevent the turbid water from dropping abruptly. Can be prevented from being destroyed, and a large floc can be sent to the outer cylinder. Therefore, flocs can be sedimented and deposited in a short time.

In addition, since the floc is always deposited in the outer cylinder above the position of the turbid water outlet of the inner cylinder, the floc in which fine particles not appropriately agglomerated and contained in the turbid water are deposited. Can be captured as a filter, the number of fine particles floating in the treated water can be reduced, the treatment capacity can be increased, and the occurrence of environmental pollution and the like can be prevented.

Further, since the electrode tank and the separation tank can be easily separated and the processing capacity can be increased, the whole apparatus can be reduced in size and can be easily transported to various construction sites. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of an electrode tank of the embodiment.

FIG. 3 is a cross-sectional view illustrating a configuration of a separation tank of the above embodiment.

FIG. 4 is a block diagram showing a control unit of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Turbid water treatment apparatus 2 Electrode tank 3 Separation tank 4 Power supply device 5 Control part 21 Anode electrode 22 Cathode electrode 23 Shower ejection means 31 Inner tube 32 Outer tube 34 Turbid water outlet 35 Partition plate 40 Stirrer blade 44 Flock upper limit detecting means 51 Electrode Switching means 52 Flock discharge control unit 53 Discharge timer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI C02F 1/465 (58) Investigated field (Int.Cl. ⁷ , DB name) C02F 1/46 B01D 21/08-21/30

Claims (2)

(57) [Claims] An electrode tank, an electrode switching means, a separation tank and a floc discharge control means disposed at a stage subsequent to the electrode tank , wherein the electrode tank is made of an aluminum alloy plate connected to an anode of a DC power supply.
Aluminum alloy connected to the electrode consisting of
A plurality of electrodes are alternately arranged along the flow direction of the muddy water, and the electrode switching means switches the connection between the DC power supply and each electrode at predetermined time intervals to switch the polarity of each electrode. Has an inner cylinder and an outer cylinder, the inner cylinder is provided vertically in the outer cylinder, has a turbid water inlet at an upper end, and a plurality of turbid water outlets is provided in a plurality of stages in a vertical direction on a lower side wall, A plurality of partition plates are horizontally mounted inside, each partition plate has a muddy water passage at a different position for each adjacent partition plate, the outer cylinder has a conical shape with a tapered lower part, and a sludge discharge port at a lower end part. A floc having an overflow outlet at an upper end portion, a stirring blade provided in a lower conical portion, and a floc defining an upper limit position of floc accumulation at an intermediate portion between the upper overflow outlet and the turbid water outlet of the inner cylinder. and a limit detecting means, flock discharge control means, floc deposited on the outer cylinder off
From the lock limit height to the upper end of the turbid water outlet of the inner cylinder
To detect the time until it decreases, and
Output timer, and the above-mentioned flock upper limit detection means
While rotating the stirring blades when the limit height of
From the sludge outlet at the bottom of the outer cylinder
Started discharging mud and reached the time set in the discharging timer
A turbid water treatment device characterized by sometimes stopping the discharge of sludge . 2. An electrode tank, an electrode switching means, and a step subsequent to the electrode tank.
It has a separation tank and flock discharge control means provided, and the electrode tank is made of an aluminum alloy plate connected to the anode of a DC power supply.
Aluminum alloy connected to the electrode consisting of
Multiple electrodes are alternately arranged along the flow direction of muddy water
The electrode switching means performs direct current at predetermined time intervals.
The polarity of each electrode is switched by switching the connection between the power supply and each electrode, the separation tank has an inner cylinder and an outer cylinder, and the inner cylinder is installed vertically in the outer cylinder.
With a turbid water inlet at the upper end and multiple turbid water
Water outlets are provided in multiple stages in the vertical direction, and multiple
Dividers are mounted horizontally, each divider is adjacent to the divider
Each has a turbid water passage at a different position, and the lower part of the outer cylinder is tapered.
It has a conical shape, has a sludge outlet at the lower end, and overflows at the upper end.
It has a water discharge port, and stirring blades are provided in the lower conical part
Between the overflow outlet at the top and the turbid water outlet at the inner cylinder
Flock upper limit detection
It has a step, and a floc pile is located at the upper end of the turbid water outlet of the inner cylinder.
And a flock discharge control means for determining the product lower limit position.
Rotating the stirring blades when the limit height of the lock is detected
While removing the floc accumulated from the sludge discharge port at the bottom of the outer cylinder
Starts discharging sludge,
Contamination occurs when the lock is reduced to the upper end of the turbid water outlet of the inner cylinder.
A turbid water treatment device characterized by stopping discharge of mud.